Buttons: Types, Sizing, and Sewing Them On

Button types

• Flat (sew-through)

  Two or four holes through the face. Use on shirts, blouses, light dresses, cardigans, and other thin fabric. Two holes for fine shirting. Four holes for anything that will be pulled.

• Shank

  A stem or metal loop on the reverse, no holes through the face. Use on coats, jackets, thick knitwear, and upholstery. The shank lifts the button so the buttonhole side can sit flat.

• Self-shank

  The shank is part of the button body. Use on coats and jackets when you want an unbroken face.

• Toggle

  Elongated so it passes through a loop rather than a slit buttonhole. Use on duffle coats, chunky cardigans, and bags. Pair with a rouleau or leather loop.

• Covered button

  A metal shell plus a snap-on back plate. Use when you want the button to match the garment. Sold as blank kits. Use a light fabric so it tucks into the back plate.

• Jeans button or tack button

  A pin hammered through the fabric into the cap. Not sewn. Use on denim waistbands, workwear, and bag flaps. Mark twice. Placement mistakes are permanent.

• Stud and snap

  Two-part, set with pliers or a press. Use on western shirts, children's clothes, and bag closures. Faster than a buttonhole. Not for high tension.

Shop buttons by size and material, or the wider sewing notions and supplies basket.

Button sizes in millimeters

Choose by diameter in millimeters. Some patterns use the older unit ligne (L): 1L is about 0.635 mm, so a 40L button is about one inch across.

Sizing by garment

• Dress shirt: 18L on the front, 16L on collar and cuffs.
• Blouse or light dress: 18L to 24L.
• Trouser waistband: 24L to 28L, flat four-hole.
• Cardigan: 24L to 28L, with a shank or a generous thread shank.
• Blazer: 30L to 34L on the front, 20L to 24L on the sleeves.
• Coat: 36L to 45L, shank, with a backing button.

The button should be no wider than half the width of the placket or band it sits on.

Materials and care

Cover buttons with foil or a pressing cloth when you iron.

Thread and needle

• Shirts and blouses: all-purpose polyester, used doubled.
• Coats, jackets, bags: buttonhole twist or topstitch thread, single.
• Knitwear: polyester, doubled, plus a backing button.
• Skip cotton thread on anything under high strain. It has less abrasion resistance than polyester.
• Wax doubled thread on beeswax or a thread conditioner.

Needle: a sharps in size 5 to 8 for most buttons. Size 1 to 4 for buttonhole twist. Needle types and sizes →

Shop sewing thread and hand sewing needles.

Sewing a button on

The thread shank is a small column of thread between the button and the fabric. It gives the buttonhole layer somewhere to sit.

1. Mark the position. Fasten the garment as it will be worn and push a pin through the buttonhole. Mark where it lands, at the end nearest the garment edge.
2. Anchor without a knot. Two or three tiny stitches on the right side at your mark.
3. Add a spacer. A toothpick, a matchstick, or the shaft of a second needle across the top of the button. A matchstick for a coat. A needle for a blouse.
4. Stitch through. Four to six passes through each pair of holes, over the spacer. On a four-hole button, parallel bars are the shirt standard. A cross is stronger.
5. Wrap the shank. Remove the spacer. Lift the button, bring the needle up between the button and the fabric, and wrap the thread column three to five times.
6. Secure and bury. Take the needle to the wrong side, work two half-hitches into the existing stitches, then run the thread between the fabric layers before cutting.

Shank height matches the buttonhole layer, not the button. Two layers of shirting need barely a millimeter. A wool coat front with interfacing and facing needs 3 to 4 mm.

Shank and heavy buttons

A shank button already has its gap. You may still want a short thread shank on a very thick coat, and you almost certainly want a backing button. Stitch through the loop six or more times in the same small spot. Interface behind the button, not only behind the buttonhole.

Buttonholes that fit

Buttonhole length equals button diameter plus button thickness plus 3 mm ease.

• Horizontal: waistbands, cuffs, jacket and coat fronts, anywhere with sideways strain.
• Vertical: narrow interfaced plackets with low strain, which is why shirt fronts use them.
• If you are not sure, use horizontal.

• Always interface behind a buttonhole.
• Push a pin across the inside of each bar tack, then cut between them.
• Sew all buttonholes before any buttons.

Placement

Put a button at the fullest point of the bust, then space outward from it.

• Shirt or blouse: 7 to 10 cm apart.
• Coat: 10 to 13 cm apart, usually an odd number.
• The button center should sit at least its own radius plus a few millimeters in from the finished edge.
• Pin every button first and try the garment on.

Quick answers

What is the difference between a shank button and a flat button?

A flat button has holes through its face and sits against the fabric. A shank button has a stem or loop on the back and holds the face above the fabric.

What does 24L mean?

About 15 mm across. L is an older button-size unit: 1L is about 0.635 mm.

How long should a buttonhole be?

Diameter plus thickness plus 3 mm. Test on a scrap with the same layers.

Are corozo buttons machine washable?

Yes. Color goes through the button. Shell and horn need more care. Both are brittle and can crack under heat.

How many buttons does a shirt need?

Typically six to eight down the front at 7 to 10 cm spacing, plus one per cuff and one at the collar. Work outward from the fullest point of the bust.